The present invention relates to an appliance and a safety device for a clothes dryer, and especially to a lint collector and safety system for the exhaust of a clothes dryer. In particular, the collector and safety system is adapted to be attached to a clothes dryer and for example in the absence of an adequate flow of exhaust air from the dryer, the system interrupts the electrical power to the dryer until such time as an adequate flow is available. In addition the safety system may interrupt the electrical power to the dryer for other dryer malfunctions.
Domestic clothes dryers typically have a chamber into which the wet clothes are placed for drying. Heated moist air is exhausted from the drying chamber through a screen that is intended to collect lint from the clothes. The exhaust air then typically passes through a duct that runs from the dryer to the exterior wall of the building so that the heated moist air is exhausted to the exterior of the building. The exhaust of the duct usually has a screen or flap that is intended to prevent rodents from entering the duct pipe. In practice, the screen at the dryer rapidly becomes covered in a layer of lint, and should be removed and cleaned, after or before every load that is dried. In many instances the screen is cleaned less frequently. Moreover, the screen at the dryer is not 100% effective in removing lint from the exhaust air, and further lint collects in the duct and especially at any screen located at the exterior of the building or elsewhere in the duct work. In addition, cleaning of the screen will often cause lint to fall into the duct and thus increase the lint clogging the duct work in the building.
In multi dwelling buildings typically an additional lint trap of very fine screen is installed down stream from the dryer lint trap. The term multi dwelling building is meant to cover both residential and commercial buildings that have clothes dryers including apartments, condominiums, hospitals, nursing homes, cleaners and the like. This lint screen is often located in a place that is awkward to reach and difficult to clean. The screen inevitably clogs up very quickly with lint and for safety reasons should be cleaned after every use. As a result of difficulties in reaching and cleaning the screen, people frequently remove and dispose of the lint trap screen. This has the effect of permitting lint to pass into the duct and collect in the duct and/or at an in-line booster fan that is typically located in the exhaust ducting and required by law in some jurisdictions. If the fine screen is removed, the blades on the booster fan will become gummed up with lint, which restricts circulation of exhaust air through the duct, creates a back pressure and lint build-up in the dryer and duct, and ultimately could result in a fire.
The build-up of back pressure in clothes dryers results in increased energy costs in order to dry the same load of clothes. Dryer time inevitably increases in relation to the amount of lint build up on the lint screen and in the duct work. An increase in drying time to as much as double that of the optimum drying times can increase by four to five times if the lint screen is cleaned infrequently.
In multi dwellings buildings, dryer ducting and in-line boost fans need to be cleaned at least once a year, even when the dryer lint screen and the in-line lint trap are used properly. Similarly, the screen and ducts at the exterior of a home needs to be cleaned with the same frequency.
Lint inevitably carries germs and viruses. When the lint trap screen becomes blocked, lint is forced out of the ducting system through any existing joints that are not adequately sealed. Consequently, lint particles leak out and spread through the air in the residence, carrying with them germs and viruses. Also when the lint screen is cleaned lint particles will typically be released into the home or multi dwelling building.
Fires can be caused by inadequate cleaning of dryers, lint screens and ducts in the dryer exhaust systems. The fires can be caused by overheating of fans or heating systems of the dryer and are spread by the lint in the dryer, in the duct and on the fan blades.
Systems to intercept lint in the dryer exhaust system are known. For example, the lint interceptor described in U.S. Pat. No. 4,115,485 is free of filters, screens or the like, to eliminate overheating of the associated dryer due to increased back pressure caused by clogging of screens or filters. The air from the lint interceptor is exhausted directly into the room, which eliminates further sources of back pressure.
U.S. Pat. No. 5,628,122 describes a lint remover that utilizes the water discharge of a clothes washer.
U.S. Pat. No. 2,577,104 describes a dryer safety control that has a counterweighted vane with electrical contacts, in which the vane on reduction of air flow closes the electrical contacts. Such a control would be very susceptible to deposits of lint on the electrical contacts and/or vane.
U.S. Pat. No. 3,639,998 utilizes a fan that would be susceptible to deposits of lint, and measures pressure drop across a screen.
A lint collector and safety system for the exhaust of a clothes dryer would be very useful, especially in reducing the likelihood of fires, and consequent injury or death of occupants of the house or multi dwelling buildings, as well as for more efficient drying of clothes.
A lint collector and safety system that is adaptable to a variety of situations has now been found.
Accordingly, one aspect of the present invention provides a lint collector and safety system for the exhaust of a clothes dryer, comprising: a housing, said housing having an inlet and an outlet in an upper surface of the housing for passage of exhaust air from the dryer, said inlet being adapted for attachment to the dryer, said housing having a water reservoir, said inlet being disposed such that exhaust air from the dryer is directed into the surface of water in the water reservoir, said outlet have a flow meter therein, said flow meter being adapted to cause an interruption in the electical circuit of the dryer if flow of exhaust air decreases below a pre-determined limit.
Another aspect of the present invention provides a safety system for a clothes dryer, said dryer having an outlet pipe for conveying of exhaust air from the dryer, said outlet pipe having a flow meter therein, said flow meter being adapted to cause a break in the electrical circuit of the dryer if the flow of exhaust air decreases below a pre-determined limit. The safety system may include an electrical field which xe2x80x9celectrocutesxe2x80x9d lint that passes therethrough. The safety system with the electrical field may be housed inside the dryer.
A further aspect of the present invention provides a clothes dryer comprising: a chamber to receive and retain clothes to be dried; an air inlet to said chamber, said air inlet having means to heat air entering the chamber through said air inlet; an air outlet to said chamber, said air outlet having a fan therein for withdrawal of air from the chamber, means to feed air from said fan to a lint collector system, said lint collector system having a housing with an inlet, an outlet and a water reservoir, said inlet being disposed such that air is fed from the fan into the water reservoir and then to said outlet.
Yet another aspect of the invention provides in a clothes dryer having a chamber to receive and retain clothes to be dried, an air inlet to said chamber with means to heat air entering the chamber through said air inlet to a pre-determined temperature, means to control said clothes dryer, an air outlet to said chamber, a lint screen in said outlet and a fan for withdrawal of air from the chamber through said lint screen, the improvement comprising replacing said lint screen with a exterior lint collector system having a housing with an inlet, an outlet and a water reservoir, said lint collector system being located such that air withdrawn from the chamber by the fan is passed from the fan through the inlet of the lint collector system and directed onto water in the water reservoir.
A further aspect of the invention provides an electrical socket for receiving a dryer plug and a connection to a safety system. The electrical socket includes a socket for providing power to the dryer plug; a connection to the safety system for providing power to the safety system and for receiving signals from the safety system; and a method for interrupting power to the dryer response to predetermined signals from the safety system. The predetermined signal may be responsive to air flow dropping below a predetermined level, time or use being above a predetermined time, temperature being above a predetermined limit or the water in the safety system being below a predetermined level.
Further features of the invention will be described or will become apparent in the course of the following detailed description.